JPH0121555Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a feedthrough capacitor.

Among the feedthrough capacitors, there is one shown in FIG. 1, for example, in which the size of the capacitance can be adjusted while keeping the external dimensions the same. This feedthrough capacitor 1 includes a cylindrical dielectric 2 . A radially outward step portion 2a is formed at the upper end of the outer peripheral portion of the dielectric body 2 for supporting the capacitor 1 on a chassis or the like. Of this dielectric 2,
Inner and outer electrodes 3 and 4 are provided on the outer periphery, respectively. The center conductor 6 is inserted into the hole 5 surrounded by the inner circumference. In such a configuration,
In order to increase the capacitance while keeping the outer shape the same, it is necessary to increase the diameter of the hole 5 and make the dielectric 2 thinner in the radial direction. For this reason, the lower half of the dielectric 2 becomes weak in strength and may be damaged during handling, especially during the formation of the electrodes 3 and 4. In addition, in such a configuration, after the center conductor 6 is inserted into the hole 5, the solder 7 is filled, and then the solder 7 is filled with the solder 7.
Even if the center conductor 6 is fixed in the hole 5 by solidification, the solder 7 melts again due to the heat generated when attaching the feedthrough capacitor 1 to a chassis etc. with solder, and as a result, the center conductor 6 becomes as shown in the figure. Downward (vertical)
It may fall off. In order to prevent this, it is preferable to press fit a collar 8 into the center conductor 6 to prevent it from falling off, but this collar 8 may damage the thin conductor 2.

An object of the present invention is to provide a feedthrough capacitor whose capacitance can be adjusted without changing the outer diameter while maintaining sufficient mechanical strength of the dielectric.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a longitudinal sectional view of an embodiment of the present invention.

This feedthrough capacitor 10 has a cylindrical dielectric 1
1. At one end of this dielectric 11, its outer diameter is enlarged to form a radially outward step 12. Inner and outer electrodes 15 and 16 are formed on the inner and outer peripheral portions 13 and 14 of the dielectric 11, respectively.

A center conductor 18 is inserted through the center hole 17 surrounded by the inner peripheral portion 13 . This center hole 17 is filled with solder 19.

The inner diameter of the center hole 17 is smaller at one end of the dielectric 11 than at the other end, thereby forming a radially inward step 20 in the inner circumference 13. In the middle part of the center conductor 18, the center conductor 18
A flange portion 21 is formed by bulging out. The flange portion 21 is adapted to be engaged with the radially inner step portion 20 when the center conductor 18 is inserted into the center hole 17 from one end side of the dielectric 11 .

In such a configuration, in order to adjust the capacitance without changing the outer shape of the dielectric 11, it is preferable to change the diameter of the center hole 17 between the stepped portions 12 and 20.

Further, by changing the length of the radially inner step portion 20 in the axial direction, the capacitance can be adjusted without changing the outer shape of the dielectric 11. In this case, the stepped portion 20 and the stepped portion 12 may be overlapped with each other. Furthermore, since both ends of the dielectric 11 are formed thickly by the step portions 12 and 20, the mechanical strength of both ends of the dielectric 11 is improved. This prevents the dielectric 11 from cracking during handling such as when forming the inner and outer electrodes 15 and 16 or when inserting the center conductor 18 into the center hole 17. Furthermore, when the feedthrough capacitor 10 is attached to the chassis by soldering, even if the solder 19 in the center hole 17 melts again, the collar portion 21 is received by the stepped portion 20, so that the center conductor 18 falls out from the center hole 17. This will be prevented. Note that in the feedthrough capacitor 10 configured in this manner, the portion of the center conductor 18 protruding from the dielectric 11 may be bent and soldered to, for example, a patterned conductive portion of a printed circuit board (not shown). In such a case, by embedding at least a portion, preferably all, of the flange 21 of the center conductor 18 in one side of the dielectric 11, the center conductor 18
The capacitor 10 can be easily bent from the proximal end of the protruding portion or the vicinity thereof, thereby preventing the feedthrough capacitor 10 from being damaged or being installed at an angle on a printed circuit board or the like.

As explained above, the present invention includes a cylindrical dielectric body, the outer diameter of one end of which is enlarged to form a radially outward step part, and electrodes are provided on the inner and outer periphery of the dielectric body. In a feed-through capacitor in which a center conductor is inserted into a center hole surrounded by an inner periphery and the center hole is filled with solder, the inner diameter of the center hole is smaller at one end of the dielectric than at the other end. The middle part of the center conductor is made smaller at the side to form a radially inner step, and when the center conductor is inserted into the center hole from one end side of the dielectric, the radially inner step is formed. The outer shape of the feed-through capacitor cannot be changed in any way by adjusting the diameter of the center hole or the axial width of the radially inner step. You can adjust its capacity without any problem. In addition, compared to conventional dielectrics in which both ends of the dielectric are thickly formed with stepped sections and one end is formed thinly, the mechanical strength is stronger despite the fact that the outer shape does not change at all. The dielectric does not break during handling, such as when forming the inner and outer electrodes on the inner and outer peripheries of the dielectric, or when inserting the center conductor into the center hole. Furthermore, when attaching the feedthrough capacitor to the chassis by soldering, even if the solder in the center hole remelts, the collar is received by the radially inward step, so the center conductor does not fall out from the center hole. Effects such as prevention can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional example, and FIG. 2 is a longitudinal sectional view of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 11...Dielectric material, 12...Step part, 13...Inner peripheral part, 14...Outer peripheral part, 15...Internal electrode, 16...
...External electrode, 17...Center hole, 18...Center conductor, 19...Solder, 20...Step part, 21...Brim part.

Claims (1)

[Scope of utility model registration request] It has a cylindrical dielectric body, the outer diameter of one end of which is enlarged to form a radially outward step, electrodes are provided on the inner and outer peripheries of the dielectric body, and a central hole is surrounded by the inner periphery. In a feed-through capacitor in which a center conductor is inserted into the dielectric and the center hole is filled with solder, the inner diameter of the center hole is made smaller at one end of the dielectric than at the other end. A stepped portion is formed, and a collar portion is formed in the intermediate portion of the center conductor to be engaged with the radially inner step portion when the center conductor is inserted into the center hole from one end side of the dielectric. A feed-through capacitor.